Dragon fruit grow on the pitaya cactus, sometimes called a dragon fruit tree because of its shape. The trunk of the cactus grows to approximately 4 feet tall, then branches into many fruit-bearing limbs. Two dragon fruit cacti can produce between 400 to 500 pounds of fruit per year, according to the University of Florida Extension Service. Two plants are needed because the cacti are not self-pollinating. The flowers open at night for only a few hours and need to be pollinated immediately by bats or moths. If fruit do not set, consider hand-pollinating the next time flowers appear.
Plant the dragon fruit tree in full sun or partial shade, in a hole three to four times the size of its container. Add 4 to 5 pounds of organic compost to the soil and fill the hole, keeping the cactus at its original planting depth. Firm the soil and water deeply to settle the soil.
Water the cactus during dry weather. Dragon fruit trees are cacti and do not like wet soil, but they need regular watering while fruiting. Give approximately 1 inch of water each time, then allow the soil to dry out before watering again.
Mulch around the outside of trunk with 3 to 6 inches of organic mulch, but do not allow the mulch to touch the trunk.
Wait approximately one month after planting to fertilize. Then fertilize every two months with a balanced fertilizer such as 10-10-10. Spray with a micronutrient spray monthly during the spring and summer.
Build a strong T-shaped trellis, approximately 4 feet high, to support the branches.
Prune the cactus to prevent side branches until the trunk reaches the top of the trellis, removing any side sprouts as they appear. Once the cactus reaches full height, cut off the growing tip to encourage branching.
Tie the main truck and branches loosely to the trellis with cotton twine.